Emulsions are widely used in industries to produce sol-gel, drugs, synthetic materials, and food products. Recent developments in microfluidic emulsion technology provided tools for precise sampling and processing of small reagent volumes. However the monodispersity of droplets smaller than 1 pm is difficult to achieve and the presence of satellite droplets along with large primary droplets produce undesirable volumes and contaminations to sample reagents. The presence of satellite droplets reduces production precision of emulsification products.
Satellite droplets are prevalent in almost all techniques of droplet generation except for a few that are currently patented in inkjet industries. In one filtration system, which uses a planar bifurcating geometry, separation of primary droplets from satellite droplets occurs, but only occasionally. Furthermore, no active control is available.
Current submicron emulsification techniques generally results in large size distributions. There are no known digital mixing techniques for submicron droplets. Currently, emulsions are extracted into different processors to generate the final products. The transport process may result in droplet coalescence and the reduction of the contents encapsulated in emulsions.
Submicron emulsions are commonly used in pharmaceutical, cosmetic, food, and material industries to synthesis drugs, creams, and nanoparticles. Recent developments of droplet microfluidics have further provided tools for digital mixing of reagents in small volumes and have been concurrently used in crystallography, analyzing DNA, and nano-particle production. Monodispersed submicron emulsions are difficult to create due to the noise generated by the high stress required to produce the small sizes. The creation of submicron droplets generally results in wide size distributions making it difficult to have precise quality control over the emulsification products.
It is desirable to provide a system that allows for active sorting of satellite droplets, and where the individual droplet sizes can be selected to go into the desired processing channels.